Brent Atatise, 34, had sought to overturn the sentence that will see him imprisoned indefinitely with no set release date. He claimed Queen's Bench Justice Don Bryk was too harsh in ruling he poses an extreme risk to the public. Atatise sought a fixed sentence, along with a long-term offender designation that would see parole-type conditions imposed on him for a decade.

But the Court of Appeal disagreed in a decision released this month, citing Atatise's criminal history. He has 15 convictions for violence, including seven sexual-assault offences. His most recent crime involved molesting an eight-year-old boy at the Red River Exhibition in 2008.

Atatise had also sought to have that conviction overturned, but was also rejected.

"The Crown has satisfied me beyond a reasonable doubt that Atatise constitutes a threat to the life, safety or physical or mental well-being of other persons on the basis of evidence establishing a pattern of repetitive behaviour by him," Bryk said in his sentencing decision earlier this year.

"As of the date of the hearing, he had been out of custody for only 2 1/2 of the 15 1/2 years since turning 18. During that time, he was placed on numerous probation orders and failed to successfully complete even one. His history within the correctional system includes numerous threats and abusive behaviour to Correctional Services staff and inmates."

Atatise was found guilty last year of attacking the young boy on three occasions in one day. The victim told court Atatise threatened to kill his family if he told anyone what happened inside a teepee and washroom at the Red River Ex, as well as at the Portage Place mall.

The victim's mother testified she had no idea about Atatise's background when she began dating him in the spring of 2008.

Atatise was on probation at the time of the most recent attack, despite having been charged at least 10 times for breaching conditions of a court order after his release from Stony Mountain Institution in 2005.

He was doing time for a sexual assault on a 15-year-old girl in 2002. He was denied parole and served his entire three-year sentence for that crime because the National Parole Board concluded he was a high risk to offend, according to court documents obtained by the Free Press.

Atatise was first convicted in 1994 of sexually assaulting two young girls. He was also found guilty in 1995 and 1997 of sexual assault, and again in 2002. The board said Atatise refused sexual-offender treatment and it didn't believe there were programs in the community that could help him control his "violent and sexual impulses." Winnipeg police warned the public about Atatise when he was released from prison on Aug. 4, 2005.

Atatise has been diagnosed as suffering from "anti-social personality disorder" and displaying "significant psychopathic traits."